The present invention relates to a member coated with a ceramic material suitable as a member which rotates at high-speed, and a method of manufacturing the same.
A member which slidingly rotates at high speed, such as a compressor shaft, an engine cam shaft, a laser scanner in a laser printer, a guide rod in a printer, etc., tends to wear easily. When wear occurs in such a fast-rotating member, this degrades the overall performance and shortens the service life of the entire apparatus. For this reason, a hard, anti-wear material such as high-speed steel or super hard alloy is often used for a member which slidingly rotates at high-speed. However, since such a material involves high material and processing costs, an increase in the total cost of the apparatus is thus inevitable. In order to decrease the total cost, a relatively inexpensive material such as cast iron or free-machining steel is sometimes used, and the surface thereof is hardend or smoothened. A technique for forming a hard ceramic such as TiN or TiC, to improve the anti-wear property of a cutting tool, has been proposed.
However, surface-hardening treatment is often performed by means of quenching, and a smoothening treatment is often performed by means of a tuftride treatment, a perco treatment, or black molybdenum disulfide coating. Neither finishing treatment can impart to the treated member satisfactory durability against the stress of use at a high load and high speed.
The tuftride treatment and quenching both require a treatment temperature as high as 500.degree. C., and the base material may become deformed, as a result. If a member requires high dimensional precision, these treatments cannot then be used.
If a TiN or TiC film is formed on a member designed for slidingly rotating at high speed, the mated sliding member becomes worn, since the TiN or TiC film is harder than the material of the mated member. Worn metal chips become attached to the ceramic layer and caused to be baked on the layer.